1. Field of the invention
The present invention relates to a camera shake correcting apparatus for use in a camera having a built-in video tape recorder.
2. Description of the Background
U.S. Pat. Nos. 5,016,112 and 4,998,162 both describe video cameras and U.S. Pat. No. 4,542,419 describes a recording and reproducing apparatus for use in a video camera. Conventional video cameras all require some sort of camera shake correction, and U.S. patent application Ser. No. 673,783, assigned to the assignee hereof, describes camera shake correcting processing circuitry for video cameras, for example.
Camera shake is the undesired effect that occurs when the cameraman takes a picture of an object with a video camera and the detected image moves in the up, down, right, or left directions as caused by the unintentional shaking action of cameraman's hands or body. The detected image may also move in a complex fashion, such as when it moves in oblique or circular directions or the like. More specifically, if the video camera is moved delicately or moved coarsely, depending on differences among individuals, then the light from an object is moved on a target screen of a charge coupled device (CCD) in various corresponding directions, such as up, down, right, and left, so that when the detected image is reproduced on the picture screen of a television monitor or the like, the reproduced picture is constantly moved in the same up, down, right, left, or oblique directions and appears to shake.
FIG. 1 shows an arrangement of a conventional video tape recorder having a built-in camera and including a camera shake correction system. In the system of FIG. 1 the elements are labelled with their conventional functions and, a motion vector of a picture that is moved by reason of the camera shaking is detected and the address of a cut-out frame of the CCD image is changed, thereby correcting the camera shake. The picture is cut out from the CCD scanning area by changing the cut-out frame so that an area in which the cut-out frame is moved in response to the camera shake must be prepared within the CCD scanning area. As a result, the scanning area is substantially reduced in size. To solve this problem, the picture area whose picture frame is reduced is zoomed up or enlarged by digital signal processing and extended to the normal picture frame. There are then present the disadvantages that the picture size is changed and the resolution of the reproduced picture is lowered.